Telephone-exchange system



2 Sheets-Sheet 1.

(No Model.)

J. P. FREEMAN.

TELEPHONE EXCHANGE SYSTEM.

No. 308,248. Patented Nov. 18.v 1884.

ill"

2 Sheets-Sheet 2v J. P. FREEMAN. v TELEPHONE EXCHANGE SYSTEM.

(No Model.)

I No. 808,Z48.

Patented Nov. 18,1884.

JAMES P. FREEMAN, OF CHICAGO, ILLINOIS.

TELEPHONE-EXCHANGE SYSTEM.

SPECIFICATION forming part of Letters Patent No. 308,248, dated November18, 188% Application filed July 30, 1684.

To all whom it may concern 13e it known that 1, JAMES P. FREEMAN, acitizen of the United States, residing at Ohicago, in the countyof Cookand State of Illinois, have invented certain new and useful Improvementsin Telephone-Exchange Systems, of which the following is aspecification, reference being had therein to the accompanying drawings.

My invention relates to telephone-exchange systems; and it consists in anovel construction' and arrangement of the parts, which will be morefully hereinafter described, and pointed out in the claims.

The object of my invention is to provide means for establishing a quickcommunication between any number of telephonic subscribers, and, bymeans of suitable colors representing like conducting bars arranged inbenches or steps, confusion is avoided in intercommunication by theoperator, whether there be a large or small number of said steps orbenches, by merely connecting bars of like colors. I attain theseobjects by the device illustrated in the accompanying drawings, formingapart of this specification, and wherein like letters refer to similarparts, and in which Figure 1 is a perspective view of my improvedexchange system. Fig. 2 is a trans verse Vertical section thereof. Fig.3 is a detail view of one of the plugs or steps, showing its connectionto the rear or line plates. Fig. 4 is a detail view of one of theconducting-bars of metal. Fig. 5 is a detail view showing the manner ofputting the conducting and non-conducting bars together, and theplug-contact rod resting against the conducting-bar. Fig. 6 is a detailview showing the manner of applying the line-plates to the rear of thebenches or steps. Fig. 7 is a detail view showing a modification inthereonstruction of the conducting and non-conducting bars.

A A represent the steps or benches of my improved exchange system, whichmay be of any number and proportion.

B is the annunciator, which is secured to the benches A A in anysuitable manner.

0 G are the drops of the annunciator, with (No model.)

the usual figures on their faces, and operated in the well-known way bycoil and armaturelever.

D represents the plugs or stops, which are cylindrical in form and havesecured to their ends a contact-rod, E, which is connected to aline-plate, F, at which the line-wire terminates by means of a spring,G, the other ends of said stops or plugs D being suitably headed, withnumbers or letters on their faces corresponding to those on theannunciatordrops 0.

I I are the ground-plates, against which the contact-rods on plug D restwhen not in use, and which are all connected to ground.

K represents the local battery to the operators telephone. 1, 3, and 5are bars of conducting material, preferably metal, which are insulatedfrom each other by means of non-eonducting bars 2, 4, and 6, of suitableinsulating material, such as wood or rubber. These conducting andnon-conducting bars are arranged alternately and parallel, and form thesteps or benches of my improved exchange system, the plugs D and theircontact-rods E having free motion in grooves or slots 0 0, out there in,as shown in Figs. 4. and 5.

M M are the ground-wires running from the ground-plates I I.

S is a switch of the ordinary form connecting the metal conducting'bars1, 3, and 5 with the operators telephone.

9 g g are the wires connecting the conducting-bars 1, 3, and 5 to theexchange operators switch S.

S S are the switches connecting the listeners or loop in telephone tothe bars 1, 3, and 5 by means of wires a a a, running from'said switchesto the conducting-bars.

To construct my improved exchange system, proceed as follows: Provide anannunciator, B, of the ordinary form, with the numbered drops 0,actuated by the magnetic attraction and repulsion of an armature-lever011 a coil, as is usual. conducting-bars 1, 3, and 5, and arrange themparallel and against each other, and clamp or fasten them in anysuitable manner, so that the holes O O can all be bored, and slots 0 cutin the same by a single operation. The non- Take the required number ofconducting-bars 2, 4, and 6 are arranged in like manner and the sameoperation performed upon them, with the exception that the holes O aremade of larger diameter, for a purpose which will be presentlydescribed. These bars of conducting and non-conducting material,ofsuitable proportions,are then arranged against each other alternatelyand parallel and secured together by means of insulated screws or bolts,as is well known in the art. By the combination of these bars 1, 3, and5, and 2, 4, and 6,alternately, as described, the benches A A areformed, and to the uppermost of which the annunciator Bis rigidlysecured. A plug or stop, D, is then constructed in a cylindrical form ofinsulating material and of suitable diameter to engage with the holes 0O in the bars of conducting and non-conducting material, forming thebenches. These plugs D are provided with suitable heads, upon the facesof which are placed the numbers or letters corresponding to those on theannunciatordrops. To the other ends of these plugs a contactrod, E, issecured and extends up through the short slots 0 to aid the operator inseeing how far to draw said plug out to put it in contact with therequired strip or bar. This slot 0 O, with its smaller slot 0 in thealternate conducting and non-conducting bars when they are securedtogether in benches, forms a continuous slot extending the entire widthof the said benches or steps.

To the contact-rod E a spring, G, is secured to allow the plug D to takeits normal position when not in use. Immediately against the backportion of the benches,and partially covering the holes 0 O and slots 0of the bars 1, 3, and 2, 4, 6, is fastened a metal groundplate, I. Thisground-plate I is in turn covered by a strip of any insulating materialhaving mounted thereon the line-terminal plates F. To theseline-terminal plates F are secured the other ends of the springs G-onthe contact-rods E, said springs passing through and having freemovement in apertures i of the ground-plates I.

Vhen the rods E of plugs D are drawn away from their ground-plates I andbrought in contact with one of the conducting-bars, and consequently theground-connection thereby broken, it is put to ground through theoperators instrument, being electrically connected therewith by saidbars and their connections, so that he will be enabled to communicatewith the subscriber.

\Vhen the plugs D are not in use, their contact-rods E rest against theground-plates I I, which are all connected by wires M M to one linerunning to ground. The line-terminal plates F of the several benches areall connected up together and run by a single line from each series tothe corresponding annnn-' ciator-coil, and from thence to line.

The conducting bars 1, 3, and 5 in the benches are connected eitherbywires b b b, as shown, or by metal strips fastened to bars occupying thesame position, so as to form a continuous bar of the whole series. Torender these conducting-bars more easily distinguishable and tofacilitate the operation of my exchange system, it will be founddesirable to have each one of the conductingbars painted adifferentcolor. For instance, if 1, 3, and 5 of the first bench are colored orpainted red, white, and black, the bars in the remaining benches,occupying the same position and being electrically connected, willrespectively have the same color, so that one plug, having been placedin contact with a colored bar of one bench of a series of benches, theoperator need only place the requisite plug of any of the other bencheson a likecolored bar, when the entire series of bars, by means of theirelectrical connections, will form one entire conducting-bar.

By having the holes or slots in the non-conducting bars of largerdiameter than those of the conducting-bars a contact bearing-surface isallowed the point of rod E on the plugs D when turned slightlyto oneside to form the connection.

In Fig. 7, the series of bars of conducting and non-conducting materialare shown as being flared at their ends, said flared ends being adaptedto receive the contact-rod on the end of the plug or stop when it isturned from one side to the other, as desired, and hold saidcontact-rod, and thus dispense with the use of the grooved and slottedform, as shown in the drawings.

The operation of my exchange is as follows: For instance, if subscriberNo. 1 should wish to communicate with No. 11, he first rings thesignal-bell in his office, and the current coming in'over the line-wire1 will cause drop No. 1 of the annunciator to fall, showing the exchangeoperator that No. 1 desires to be connected with some other subscriber.The op erator at once pulls plug No. lout a sufficient distance, and indoing which breaking its ground-contact to allow the pin to engage withsome bar not in use. He then turns his switch to the same bar throughhis connecting-wire with the same, asks No. 1 which subscriber hewishes, and in answer requests No. 11. The operator now pulls plug No.11 out, breaking its ground-contact, until its contact rod E restsagainst the corresponding bar in the second bench, (see Fig. 7,) andrings up No. 11, who, upon answering his call, is told to go ahead. Assoon as the subscribers have ceased their communication, a short ring orsignal will let the exchange operator know that they are through, whenhe then turns plugs 1 and 11 far enough to release the contact-rods Efrom their contact with the bars upon which they rest, and through theresiliency of the springs G on their ends are drawn back against theground plates I, and thus grounded and ready for air other call.

I do not confine myself to the exact construction shown. For instance,the spring G may be dispensed with, and a weight'and cord attached inits place, the object of both being to bring the stop back to its normalposit-ion automatically after being released from the communicatingbars.

It will also be seen that the annunciator can be replaced bygalvanometer needles, when the action will be the same. These and otherchanges in construction can be made without materially departing fromthe nature and principle of my invention.

Having thus described my invention, whatI claim as new, and desire tosecure by Letters Patent, is

1. In a telephone-exchange system,t-he com bination of an annunciator,alternate conducting and non-conducting parallel bars arranged inbenches or steps, and stops or plugs for making electrical connections,substantially as described.

2. In a telephone-exchange system, the combination, with an annunciator,of a series of conducting and non-conducting bars arranged parallel andin benches or steps, plugs or stops with contact-rods, theground-plates, and electrical connections, substantially as described.

3. In a telephone-exchange system, the combination, with theannunciator, of a series of insulated and conducting bars arrangedparallel and in benches or steps, insulated plugs having contact-rods attheir ends, springs con-' nected to said contact-rods, theline-terminals to which the other ends of said springs are attached,theground-plates, and electrical connections, substantially as described.

4. In a telephonic-exchange system,the combination, with theannuneiator, of a stepped switch-board, composed of a series of slottedor grooved conducting and nonconducting parallel bars, secured togetherand electrically connected to form one circuit, the insulated plug, withits contact rod bearing in the grooved switch-board, the spring on oneend of said contact-rod, the ground-plates, the line terminal-plates towhich the free end of contact-rod springs is secured, and theirelectrical connections. substantially as and for the purposes described.

5. The combination, in an exchange system, of annunciator B, switchboards or benches A, composed of alternate bars of parallel conductingand non -conducting materials 1 3 5 and 2 4 6, slots or grooves O O, andsmall slot 0, plug D, contactrod E, spring G, lineterrninal plates F,ground-plates I, operators switch S, and the electrical connections,substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

JAMES I. FREEMAN.

Witnesses:

CHARLES S. HYER, IV. S. ODELL.

